Chaetomium globosum spores, SEM

Coloured scanning electron micrograph (SEM) of Chaetomium globosum spores. Chaetomium spp. occur in many different environments and can rapidly decompose cellulose substrates. Certain species possess type I and III allergens, and can produce sterigmatocystin, a mycotoxin shown to cause kidney and liver damage in laboratory animals. It is not a common human pathogen, but it has been known to cause skin and nail infections. Chaetomium is an ascomycete, and in most species the spores are lemon-shaped, with a single germ pore. Several species have been reported to play a major role in decomposition of cellulose-based materials, and is often found indoors with Stachybotrys. These fungi are able to dissolve the cellulose fibres in cotton and paper and thus cause the materials to disintegrate. The process is especially rapid under moist conditions. Magnification: x440 when shortest axis printed at 25 millimetres.